Noiseless device for generating audible voice frequencies including harmonics



July 14, 1959 5. M. WRIGHT 2,895,126 NOISELESS DEVICE FOR GENERATINGAUDIBLE VOICE FREQUENCIES INCLUDING HARMONICS Filed Nov. 12, 1957G/LAEQT 111. was:

INVENTOR.

2,895,126 I Ice Patented July 14, 1959 NOISELESS DEVICE FOR GENERATINGAUDIBLE VOICE FREQUENCIES INCLUDING HARMONICS Gilbert Wright, Malibu,Calif., assignor to Kett Enginearing Corporation, Santa Monica, Calif.,a corporation of California This invention relates to a. device forgenerating and varying voice frequencies including harmonics which isparticularly well adapted for use by afflicted persons unable tonormally produce voice sounds.

There are many afflicted persons who cannot produce voice sounds andspeak understandably because their vocal organs, such as the larynx,have been removed or injured in whole or in part; surgery necessitatedby carcinoma of the throat or larynx often destroys the power of speech.This invention relates to a small, portable device which generatesmechanical frequencies similar'to those ofthe normal speaking voice andimparts suchfrequencyvibrations to the skin of an afflicted personlinthe region of his throat to produce sound waves within thecavities inwhich natural sounds would have been normally created, such sound wavesbeing capable of modulation by the tongue and lips into understandable,audible words and sounds. However, when the device of 'thepresentinvention is not in contact with a sounding "board such as the skin ofthe cheek or throat, no objectionable sound or noise is produced eventhough the device is generating vibrations. Sound is only produced whenthe device engages a substantially solid resilient material, like theskin and flesh of a persons throat or other sheet material which acts asa diaphragm to produce sound waves. This advantage eliminatesembarrassment which maybe caused by an audible and perelectromagneticstriker means positioned within the casing and including a strikerhaving a face of reduced area adapted to strike the contact element atselectively variable frequencies. 7 An object of the present inventionis to provide a device which enables afl'licted persons, unable tonormally produce voice sounds, to speak audibly.

Another object of this invention is the provision of a device which issubstantially silent but capable of generating audible voice frequenciesincluding harmonics when in contact with a solid material.

A further object of the present invention is the provision of a novelcontact element for devices adapted to generate audible soundvfrequencies when the element is placed in contact with avibration-transmitting solid.

Other objects, uses, advantages and adaptations of the invention willbecome apparent to those skilled in the art ed drawing, in which;

Fig. 1 is a longitudinal section of an exemplary embodiment of theinvention.

Fig. 2 shows a transverse section of an exemplary embodiment taken alongplane IIII of Fig. 1.

Fig. 3 shows a transverse section of the device taken along planeIII-III of Fig. 2.

Figs. 4, 5 and 6 are a series of views illustrating the operation of themeans for varying the frequency of re-- ciprocation of theelectromagnetic striker means.

Referring now to the drawings, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in Fig. 1 a substana tially silent device 10 forgenerating voice frequencies including a casing 11, a contact element 20mounted on one end of the casing, and a striker means 30 positionedwithin the casing and adjacent the contact element 20.

The elongated casing 11 may be hollow having its ends open and isadapted to be hand held. A recticulated, virtually rigid contact element20 may be mounted on one end of the casing and is adapted to generateand transmit vibrations of audible frequencies when the element isplaced into contact with a vibration-transmitting element. The contactelement preferably has a multiplicity of passageways therethrough topermit it to transmit mechanical vibrations without acting as agenerator of air waves of such vibrations. To attain this novel anddesirable effect, the total area of passageways should exceed thefrontal area of the solid material constituting the contact element.Although various constructions maybe employed, the contact element ,20illustrated in the drawings may be made of spirally wound corrugatedmetallic ribbon 21 alternating with a non-corrugated ribbon 22, adjacentlays being firmly connected as by furnace brazing, soldering etc. toform a virtually rigid, disk-like element which has a convex outercontour adapted to be comfortably placed against the skin of the user,Fig. 2 (equivalent to a plan view) shows that the frontal solid area is"less than the total area of air passages such as 23.

Means may be provided for adjustably positioning the contact element 20with respect to the striker means 30. Such meansmay be a ring 24 havingthe contact element 20 secured on one end and the other end threadedlyand adjustably received on an open end of the casing 11. A resilientwasher or bushing 25 may be provided between the contact element 20 andthe ring 24 to prevent any mechanical or artificial sounds frombeingproduced when the contact element is set into vibration.

An electromagnetic striker means 30 may be positioned within the casingand may include a striker 31 having a face of reduced area adapted tostrike the contact element 20. The armature or striker 31 has aneffective striking face area of less than 20% and preferably less than10% of the total plan area of the contact element 20. The striker meansmay be a solenoid coil 32 in which the reciprocatable armature orstriker 31 is movably positioned, the striker being normally biased outof contact with the contact element 20 by means of the spring 33.

Means are provided for energizing the striker means 30 at will, andpreferably for varying the frequency at which striker 31 hits contactelement 20. Electrical en ergy may be supplied from a battery (capableof being carried in a pocket of a user of the device) and a flexiblecable or conductor connected to ends of coil 32. In its simplestembodiment an interrupter switch may bein troduced into one of theconductors, but this would only permit the striker to hit contactelement at a virtually constant frequency and preclude variation in toneor pitch. In the form of device illustrated, means are provided forvarying the frequency. As shown in the draw ings, the ends of theconductors from the battery are connected to terminals 34 and 35 oninsulated terminal posts 36 and 36. Terminal 34 may be directlyconnected to one end of the coil 32 whereas the other end of the coil 32is connected to .a movable, resilient contact arm 37 against whichinsulated tip 31' of striker 31 is urged by spring 33 when the coil isde-energized (a condition illustrated in Fig. 1). When in such position,an inclined or cam face 37' of contact arm 37 is immediately beneath butout of contact with contact button 38 carried by a resilient actuatingarm 38' electrically connected to terminal 35. Actuating arm 38' alsocarries an actuating push button 39 which extends through a suitableport in the casing. When push button 39 is depressed contact is madebetween contact button 38 and contact arm 37 thereby completing thecircuit and energizing coil 32 to cause striker 31 to move and strikecontact element 20. Movement of the armature or striker 31 in a strikingdirection removes tip 31 from resilient arm 37 and breaks the circuit;return of the striker closes the circuit. I

The .mode of operation of contact 37 to vary the frequency ofreciprocation of the armature or striker 31 will be described byreference to Figs. 4, and 6. As shown in Fig. 4, when contact 38 touchesthe upperend of the inclined face 37', the circuit is completed and thearmature or striker 31 begins to move to the left or is drawn Within thecoil 32. When the armature 31 moves to the left, the resilient arm 37also begins to pivot to the left and therefore breaks the circuit,assuming a position similar to that in Fig. 6, even through button 39 ispartly depressed. When button 39 is partly depressed, say only an amountsufficient to cause contact button 38 to contact the upper end ofresilient arm 37 and its inclined face 37, the striker 31 reciprocatesthrough its longest stroke and at its lowest frequency, therebygenerating the vibrations .of low frequencies in the contact element 20.By depressing button 39 a greater distance, contact button 38 preventsresilient arm 37 from moving to the right (see Fig. 6) and thereby thestroke of striker 31 is shortened and vibrations of higher frequency areset up in .contact element 20. The arrangement thus permits the user tovary the pitch of the tones formed in the cavities :of his throat andmouth by varying the position of actuating push button 39. In addition,the position of the. contact element can be varied. thereby establishing.a further change in pitch range. The user can add color, inflection andemphasis to sounds or words uttered with the sound generated by thisdevice. In practice, the device may be adjusted to generate sounds offrequencies between about 100 and 2000, although a range .of 200-700 isadequate.

While it is necessary that percussion takes. place between the armature31 and the contact elementv 20 in order to produce a vibration richenough .in harmonics to be articulated, the sound of the striking, ofthe armature on the contact element should be at .an absolute minimum. Asound-absorbing means may be provided within the casing 11 and isadapted to absorb sound generated by the striking of the armature 31against the contact element 20 or sound within the casing. As shown inFigs. 1 and 3, the striker means is. spaced from and acousticallyinsulated from the casing. 11 .by means .of strips of suitablesound-absorbing material 40 (such as felt) which form resonatingchambers Alisurrounding the striker means. The chambers, maybe ofvarious sizes and lengths to absorb any length sound waves that aregenerated within or transmitted into the casing 11. Small holes 42 areprovided in the casing 11 at suitable points to dissipate the soundwaves sent into the chambers.

It will be noted that contact element 20 is not a diaphragm and does notactually set up audible air waves when the striker 31 hits it. Thestriking face of striker 31 is also of small area and does not set upair waves of any intensity. The striking face impinges either upon theedges of the ribbons 21, 22, at the center area of contact 20 or againsta small solidportion at such center, but any air waves generated by suchpercussion are distorted and readily pass through openings orreticulations 23, or bounce back into the case and are absorbed bychambers 41. The design of the device is therefore such that when thedevice 10 is not in contact with the throat of the afflicted person, andthe operating button 39 is depressed .(thereby setting up vibrations incontact element 20) no audible sound or noise will be produced.

The vibrations produced in the contact element 20 are turned into soundonly when the contact element 20 engages the skin of the throat or cheekof the user or some other diaphragm-like object. The vibrations set upbycontact element 20 against the skin of the throat of the afilictedperson is a mechanical vibration and is turned into sound waves when thevibration reaches the air within the throat. The mass of the armature31,the mass of the contact element '20 and the resilient values of thespring 33 and of the contact element mounting are designed tomechanically match the impedance of the flesh of the throat achievingthe maximum transfer of energy to the air within the throat and causingthe minimal disturbance of the air in contact with the skin of thethroat and with the device. The skin of the throat in contact withcontact element 20 acts as a diaphragm and moves air back into thecasing as described above. As the air is trapped within thesoundeabsorbing chambers 41 as described hereinabove, a certaindesirable quality to the voice is produced, thus givingit .a fullness.Therefore, the seemingly undesirable noise transmitted backinto thecasing is used to give depth and roundness to the voice.

A substantially silent device is therefore provided for generating voicefrequencies, including harmonics, while in contact with a solidmaterial. Itshould be understood that the casing 11 is of such a sizethat it will readily fit into the pocket of the user. Any type of powersource can be provided for operating the device, such .as flashlightbatteries .or ahand-wound springmotor. With this device, a person whocannot produce voice sounds because of loss of his vocal organs can nowspeakandcommuniate with others. In addition, the voice produced by thepresent device will not produce an artificial ,or mechanical sound, butwill enable the user to speak ina normal tone having depth and quality.

Obviously many modifications and variations of the present invention arepossible in the light .of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A substantially silent device for generating voice frequenciesincluding harmonics when in contact with a solid material, comprising:an elongated, hollow casing adapted to be hand held; a reticulated,virtually rigid element adjustably mounted on one end of saidcasing,.said element having a frontal solid area which is smaller thanthe area of reticulations therethrough; electromagnetic striker meanspositioned within saidcasingand including a striker having a faceofreduced area adapted to strike theselement. at a frequency ofbetweenabout and 2 000 vibrations per second; and sound-absorbing meanssaid casing adapted to absorb the sound of blowsv delivered by thestriker upon the element without .absorhin g vibrations setup in. theelement.

2. In-the construction as stated inclairn 1,. the ,provision ofrneansfor varying the rate of energiz ation of said striker means including acircuit brokenby movement of the striker into striking relation withsaidelement.

3. A construction as stated in claim .1, wherein said elementcomprises:v spirally wound, corrugated metallic ribbon with adjacentlays firmly connected toform adisclike structure.

4. A construction as stated in claim 1, wherein said striker has aneffective striking face area of less than 20% of the plan area of saidelement.

5. A device as stated in claim 1 wherein the electromagnetic strikermeans comprises a solenoid coil and said striker comprises an armatureof said coil; a source of energy and a circuit operably connecting saidsource to said coil; and an interrupter switch in said circuit and amanually operable push button to close said circuit.

6. A device as stated in claim 5 wherein the interrupter switch includesa resilient arm biased into circuit opening position; a contact buttonmovable by said push button into contact with said arm; a spring biasingthe striker into retracted position, said striker and biasing springbeing adapted to move the resilient arm into position beneath thecontact button when the striker is retracted, and cooperative means onsaid arm and contact button to vary the stroke of the striker inaccordance with movement of the push button and contact button.

7. In the construction as stated in claim 1, the provision of means foradjustably positioning said element with respect to said striker means.

8. A substantially silent device for generating voice frequencies whenin contact with a solid material, comprising: an elongated hollow casingadapted to be hand held; a reticulated, virtually rigid element mountedon one end of said casing; a solenoid coil within said casing and areciprocatable armature in said coil, normally biased out of contactwith said element but movable to strike the element.

9. In the construction as stated in claim 8, the provision of means forvarying the length of stroke and frequnecy of reciprocation of saidarmature.

10. A construction as stated in claim 8, wherein said element comprises:spirally wound, corrugated metallic ribbon with adjacent lays firmlyconnected to form a disc-like structure.

11. In the construction as stated in claim 8, wherein said armature hasan effective striking face area of less than 20% of the plan area of theelement.

12. In the construction as stated in claim 8, the provision ofsound-absorbing means within said casing adapted to absorb the sound ofblows by the armature upon the element.

13. In the construction as stated in claim 8, the provision of means foradjustably positioning said element with respect to said armature.

14. A substantially silent device for generating audible voicefrequencies when in contact with a solid, elastic material, comprising:a hollow casing adapted to be handheld; a virtually rigid elementmounted on one end of the casing, said element being provided with amultiplicity of through passageways, the total area of such passagewaybeing greater than the total frontal area of solid portion of suchelement; electromagnetic striker means within the casing, including areciprocatable striker adapted to strike the element at a frequency ofbetween about and 2,000 times per second; manually actuatable means forenergizing said striker means; and sound-absorbing means within thecasing adapted to absorb the sound of blows delivered by the strikerupon the element.

15. An element for devices adapted to generate audible frequencies whensaid element is placed into contact with a vibration-transmitting solid,comprising: a rigid disc-like structure having a multiplicity ofpassageways therethrough, the frontal solid area of the structure beingless than the area of passageways, said structure being substantiallynon-flexible and comprising spirally wound corrugated metallic ribbonwith adjacent lays firmly connected.

16. A substantially silent device for generating audible voicefrequencies when in contact with a solid, elastic material, comprising:a hollow casing adapted to be handheld; a virtually rigid elementmounted on one end of the casing, said element being provided with amultiplicity of through passageways, the total area of such passagewaysbeing greater than the total frontal area of solid portion of suchelement; electromagnetic striker means within the casing, including areciprocatable striker adapted to strike the element at a frequency ofbetween about 100 and 2,000 times per second; and manually actuatablemeans for energizing said striker means.

17. In the construction as stated in claim 16, the provision of meansfor varying the length of stroke and frequency of reciprocation of saidstriker.

References Cited in the file of this patent UNITED STATES PATENTS1,901,433 Burchett Mar. 14, 1933 1,942,811 Green Jan. 9, 1934 2,230,762Rittenhouse Feb. 4, 1944

